In the above-described type of rail wheel, the fibrous composite structure, which constitutes the wheel disk, must transfer, in addition to the radial contact loads of the wheel and the braking and accelerative forces acting in the circumferential direction, strong transverse forces, acting parallel to the wheel axis, between the hub and the wheel tire. Accordingly, the fibrous composite structure of the wheel disk must possess a correspondingly high flexural strength. This is achieved in the known disk wheels of this type (See, e.g., German Patent No. 33 45 555 and European Patent No. 65 086), wherein the wheel disk is designed with a sandwich construction, with a characteristically light inner core of metal honeycombs or foam plastic material, which joins the outer fibrous composite surface layers, in a shear-resistant manner, at a distance to each other. Such an inner core, irrespective of whether it consists of metal honeycombs or of a foam plastic material of sufficient strength, is so expensive, that the application of rail wheels of this construction type is only possible to a limited extent, in spite of their superior qualities as compared to standard all-metal rail wheels.
It is a primary object of the present invention to design a rail wheel of the fibrous composite structure type which has a cost effective type of construction, suitable for large-scale production, and, while maintaining a low true specific weight, provides significant structural strength in the area of the fibrous composite wheel disk.